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Over the years, lithography engineers continue to focus on CD control, overlay and process capability to
meet current node requirements for yield and device performance. Use of ArFi lithography for advanced
process nodes demands challenging patterning budget improvements in the range of 1/10 nm especially
for interconnect layers.(1) Previous experimental and simulation based investigations into the effects of
light source bandwidth on imaging performance have provided the foundation for this work.(2-6) The
goal from the light source manufacturer is to further enable capability and reduce variation through a
number of parameters.(7-10)
In this study, the authors focus on the increase in image contrast that Source Mask Optimization (SMO)
and Optical Proximity Correction (OPC) models deliver when comparing 300 fm and 200 fm light source
E95% bandwidth. Using test constructs that follow current N7 / N5 ground rules and multiple pattern
deconstruction rules, improvements in exposure latitude (EL), critical dimension (CD) and mask error
enhancement factor (MEEF) performance are observed when SMO and OPC are optimized for 200 fm
light source bandwidth when compared with the standard 300 fm bandwidth. New SMO-OPC flows will
be proposed that users can follow to maximize process benefit. The predicted responses will be
compared with the experimental on wafer responses of 7 nm features to lower light source bandwidth.
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